Documentation: List of supported clouds

[Houzonglaile]

Docs page: https://juju.is/docs/juju/juju-supported-clouds

Docs source: https://discourse.charmhub.io/t/list-of-supported-clouds/6665

Issue: I would like to use JUJU on Huawei Cloud. What the things that we need to in order to implement this? We now have a team that is studying this JUJU project and try to figure out what JUJU can do for Huawei Cloud and how can we do this. We are on the step of installing JUJU client and try to deploy JUJU on Huawei Cloud.